Radiation - induced mutagensis in S. typhimurium TM677 to 8-azagnanine resistance is investigated in regards to log phase and stationary phase responses to: 1. postirradiation incubation prior to scoring for mutation frequency (MF); 2. the presence of various radiation sensitizers (misonidazole, cis-dichlorodiammine-platinum (II), paranitroacetophenone, triacetoneamine-N-oxyl); 3. the presence of various antitumor drugs (bleomycin, CCNU, L-PAM). In addition, correlation of MF expression with DNA damage will be made for these various treatments.